This invention is generally concerned with a heel holder arrangement of a safety ski binding.
A safety ski binding typically comprises a front sole holding arrangement which is operable to hold the front edge of the sole of a ski boot in position, and a heel holding arrangement which similarly locates the heel of the ski boot on the ski. In a heel holding arrangement as disclosed in German laid-open application (DE-OS) No 33 22 634, a sole holder which, when in the locking position, engages over the upper edge of the sole at the heel end of the boot thereby to fix the boot on the ski, carries at its lower end a kicker or spur portion on which the skier presses with the heel of his boot in order to fit the boot into the safety ski binding, by consequentially moving the sole holder into the locking position. So that the sole holder is always held in the condition of being ready for insertion of a boot, and also for assembly reasons, it is desirable for the movement of the sole holder out of the locking position into the release position to occur substantially automatically under the effect of the force of a spring, when an opening lever for releasing the sole holder is actuated. For that purpose, the opening lever of the above-indicated known arrangement is mounted pivotably on the sole holder, with the mounting axis for the opening lever being arranged behind and below the mounting axis for the sole holder. Therefore, when the opening lever is pressed down, the sole holder is already loaded in the direction of opening of the holder arrangement, in the first phase of the movement involved. In addition, that heel holder arrangement has a retaining lever to hold the sole holder in its locking position, and the retaining lever and the opening lever are connected by a coupling member which forms a spring plate for the compression spring which urges the sole holder from the locking position towards the release position. The sole holder further comprises a cam configuration which in turn also provides a cam detent portion or notch arranged to receive a roller carried on the retaining lever to hold the sole holder in the locking position. The cam configuration is such that the sole holder can pivot into its release position under the influence of the compression spring, by way of the retaining roller, as soon as the retaining roller has moved out of the above-mentioned cam notch. The retaining lever is mounted behind the sole holder, pivotably about an axis which is parallel to the pivot axis of the sole holder, with the retaining roller being carried on the retaining lever at its upper end. The opening lever is mounted pivotably about a third axis which extends parallel to the surface of the ski on which the ski binding is used. The compression spring of the heel holder arrangement bears against the coupling member so that the retaining lever is spring-loaded thereby and the retaining roller is thus urged against the cam configuration, thereby to define the force/travel characteristic involved in the opening movement of the sole holder. As noted above, the retaining roller can engage into a notch in order for the ski boot to be held under a spring force on the ski, while the cam configuration in the region of that notch, in conjunction with the lever arm of the retaining roller and the lever arm in respect of engagement of the spring against the retaining lever define the release time in respect of safety release of the heel holder arrangement. The cam configuration outside the notch thereof determines the force required for insertion of a ski boot into the holder, being the force which the skier must overcome by standing on the above-mentioned spur portion of the sole holder in order thereby to pivot the sole holder from its release position into its locking position. When the opening lever is actuated by the skier, to release the holder arrangement, the retaining roller is lifted out of the notch in the cam configuration so that the sole holder can pivot upwardly in an unloaded condition.
The fact that the compression spring bears against the coupling member which connects the retaining lever and the opening lever, the way in which the coupling member is disposed in the assembly, and the arrangement of the compression spring in the housing beneath the opening lever, means that the arrangement requires a relatively large amount of space while in addition the structural size thereof is increased as a result.